Perhaps it does give a false impression -- or at least it's designed to create a different impression than the map you posted. We would have to see the complete data set to really know. The map I posted is general (it also uses different definitions); but, yours could also be misleading. For instance, if the Russian-speaking population is concentrated in cities, then it would appear as a tiny part of the total area. For instance, the following map is based on "area" rather than "population of voters", and gives the impression (at first glance) that the Republicans won the 2008 presidential election in a landslide. What it really shows is that Republicans live in less densely-packed places than Democrats.